Flotation of ores



F b, 1 7, I925.

E. MALMROS FLOTATION OLE ORES Filed Dec. 30, 1920 liill llh'ftl ii 13.MMLMZRGS, 0F L'ZWNIERUUK, TLWELWV noun.

TWIMTATIU'H UL? Application flied Ttlccemhcr 30. 1920. Eleriai No.4234971.

To all via/tom it may concern iEle it known that l, i lowm' B. Mluuuuos,a sui' icot of the King of Eviction, residing iLVl'llJIOOli, in thecounty of Nassiuu tato of New York, have invented certain new antiuseful Improvements in the l lota tion of (Mes; antl I do hereby declarethe foilowiup: to ho a ifuli, clean anti exact (18-- oci'intion oi theiut'hhtion, such as; will onteruiniuotl hy the percentage ofmetalliieroua mutton therein as oom'pai'eclWith the amount oi gangguematter? therein ancl it is, of course, desirable to attain as high agrade oitcoucenti" to as is; consistent with satisfactory practice inothei' respect-s, such, for ouauiplo as the percentage of recovery ofthe metalliieroua material. Where a com oitlet'ahle amount oi gauguematerial is CF11"- riccl up into the floating mass oi mineraliafllen gashuhhleu, the oracle oi the resulting" concentrate is very likely to helong anti this is especially true in the oneumatic flotation process. 'lho present invention aims partiouiaily to improve or Yaioo the oracle ofa flotation coucontiute and. in the impro ecl t}T )tr?HlI-HS oi theinvention, this aim is accomplished by causing; the floating mass oft"ii1iiiei?al-'.l:ic'len gas bubbles to move over the miclacc of arelatively quiescent liquid rue-- tiium into which "particles of gaug'uecli'op i'uouo the floating mass aucl are retunnco'to tho hotly of orepulp undergoing the iiota tiou treatment" Who present iuveutiou is; moteuarticw lai'ly applicable to the iueumatic i'lotatio-u procesog iiiucein utoeosa a vow oouuhlctahle al'uount of gauguo ia oai'rieol into thefloating *oaaa of gait liuhhlea (on louhhle coiuiuu) aloug withthe-nictailifetous mattei, ao

that the guaole of the ioiaaultinn; couceutiato is to a large extentcletcin'iinetl lay the selective action talziu place iii mass; Oi columnof goo loulohlce, as a which thit mass U1" column of huohieo ispiogiosaivcly richer in mine 'al particles from theholtom to the topthereof. in the improved appu ratus of the present invention, tho mas;vor column of, gas bubbles resulting; from the pneumatic flotationprocess is cauacrl to move over the surface of a relatively quicscentliquid medium which is in cou'imunicw tion with the main hody of onepulp uuclen going; the flotation treatment During: the movement of themost 01 column of {fill huhbles over this quiescent liquifl iucdilu'n. asolective cleaning. action tfll iOS place as' a re sult of which a wryconsiderable quantity of gangiue particles drop from the mast; 01 columnoi? gas bubbles iiiito the liquid cliuin ancl are returned to the mainbody oi ore pulp. in this iiuani'ier, a very nriatciiial enrichment inmineral matter takes placo in the mass or column of goo huhhles, as aconsequence of which a higher giracie oi couceiutlatc ohtainetl.

The principle of operation and novel ie: JCHTOS of the apparatus of theinvention Will he hotter uulctstoorl from the following ticscriptiontalteu in conjunction with the ac companyiug thawing, illustrating; apneumatic flotation cell einhoclyiug; the invention. in this; cluawiii2:

is a transverse tatiou cell;

2 is a longitudinal section of tho ilotation cell autl 3 is av plan Viewoi the iiot-atiou coll.

Referring now partioulai iy to the iaocoinpanying thawing, the apparatusthehciu illustrated is; a flotation c ot the PHGQHM iic t vpe. As Tepr'eaentetl in the imiting the cell has a suhstuntialiv ilat bottom hanal upwai'clly and outwarcily inclined. sic'io Waiis 6, at the upperend of which one ptovioiedi the longitudinal concentrate iauntiei'a l.The bottom 5 out tho celi may loo suhstaur tially horizontal or,iiiflesii'odl, the hottoii'i may have a slight downward inclination fromthe teed encl towat'clu "1o tailingo thischarge enol.

Appropriatc means are piwwicletl for introclucing into the cell asuitable gaeoous flotation agent, such as an. iiuch means may takevarious iorims and in the con struction illustrated in the accompanying:drawing a plurality of gas or air compattments time aseociatcd with thohottoirn 5 of the cell. lrliach air compartment 8 io pro viclcxl with aiooroua medium 9, such canwas, through which ail 0E tithe" appropriateSection of the iioillilgas, may be introduced in a finely disseminatedstate into the ore pulp. Each compartment 8 is connected by a valvedpipe 10 with the air or gas main'11. By this arrangement the supply ofall or other gaseous flotation agent to each compartment 8 may beindependently controlled.

Two vertical bafiles or partitions 12 are longitudinally mounted withinthe flotation cell. The battles 12 'are arranged substantially above thelongitudinal or side walls of the compartments 8 whereby the upwardlyrising stream or current of gas bubbles passing through the porous media9 is contined between the baffles 12, and a relatively quiescent zone isprovided in the spaces between the bullies l2 and the side walls 6. .lhetops of the bullies 12 are slightly below the normaloperating liquidlevel off the ore pulp, while the bottoms of the baliles are spaced fromthe bottom ot' the cell to provide an appropriate communication betweenthe relatively quiescent zones (between the battles and the side wallsof the apparatus) and the active aeration zone (between the battles.12).

' In operating the apparatus illustrated in the drawing, in accordancewith the principles of the present invention, the ore pulp is fed intothe apparatus at the end of the cell between the inclined teed ballle'13 and the adjacent end wall of the cell. The tailings aredischargedfrom the cell through the tailings discharge outlet 14. Therate of the tailings discharge is controlled in the usual manner by afloat ball 15 and coopcrating mechanism so as to maintain the liquidlevel of the ore pulp in the apparatus at thedesired height. Air, orother appropriate gas, in introduced through the porous media 9 in afinely disseminated state into the body of ore pulp between the baflles12 and produces a supernatant or floating mass or column ofimmoral-laden gas bubbles *in.

the well understood manner. As a result of'the arrangement of thebailles 12, substantially no gas bubbles find their way into thelongitudinal space between the batlles 12 and the side walls 6, andaccordingly the liquid in these longitudinal spaces is in a relativelyquiescent state. The floating mass j or column of mineral-laden gasbubbles moves outwardly in either direction and. passes over the surface,of the relatively quiescent liquid in the longitudinal spaces betweenthe bellies 12 and the inclined side walls 6. During the passage of themass or column of gas bubbles across these relatively quiescent zones,gangue particles drop from the mass of air bubbles into the liquid inthe uiescelit zones and are returned be neath t e bottoms of the baflies12 into the active flotation zone of the apparatus. In this manner, aselective cleaning of the mass or column. of mineral laden gas bubblestakes place over the aforementioned quiescent zones and a richer orhigher rade concentrate flows into the launder than in pneumaticflotation apparatus of the here toi'ore customary types.

The apparatus of the invention p )ssesscs many features of superiorityovtr the heretotore'customary types of pneumatic fiotalion cells. In thefirst place, as a result of the enrichment oi the concentrate, it is possible to produce in one cell or apparatus a concentrate of satisfactorygrade, thus eliminating the retreatment or" concentrates and the use ofrougher and cleaner cells now generally practiced. Moreover, theinvention permits the use of a larger volume of air (or otherappropriate gas) per square foot of air-mat without blowing over andcarrying into the final concentrate an objrctionable percentage ofganguc. Consequently, a higher air pressure can be employed in ellectingthe flotation operation and on this account a fiat (or substantiallyflat) bottom cell can be employed without danger of blinding the porousmedium. Moreover, the cross currents produced in the ore pulp by thearrangement of the longitudinal ballles have a tendency to clean the topsurface of the porous medium. and. finally, the circulation around thebattles provides for a retreatment of particles once fioated'andreturned to the active flotation zone through the agency of therelatively quiescent zones.

From the foregoin description, it will be seen that in the impi vedapparatus of the invention the flotation concentration involves thefollowing three (3) steps, (1) the formation of a column or mass ofmineralladen (both metalliferous and gangue) gas bubbles, (2) a cleaningof this column or mass of gas bubbles while passing over a relativelyquiescent liquid medium, in course of which a relatively considerablepro portion of the gangue particles and a relatively much smallerpercentage of the metalliferous particles (carried upwardly into themass of gas bubbles by the flotation treatment) are permitted to dropinto the liquid medium, and (3) the return of the mineral matter (bothgangue and metalliferous),

' mac o-r a gas bubbles into the liquid medium. Accordmgly, a muchhigher or richer grade of concentrate is Withdrawn from the a "paratusvthan can be obtained; in the a sence of: the selective cleaning step ofthe invention, and to this extent, the flotation operation as a whole ismaterially improveci. ll claim 1. An apparatus lorthc concentration ofores by flotation comprising an elongated chamber, means at one end ofthe chamber for feeding ore pulp thereto, means for maintaining a lonitutlinal flow of ore pulp through the chamber, a longitudinal] frothores by flotation comprising an elongated chamber, means at one end ofthe chamber 9?; apparatus for the concentration of for feeding ore pulpthereto, means for maintaining a longitudinal flow of Olt pulp throughthe chamber, means for generating mineral laden gas bubbles over alongitudb nal area including a portion only transverselv of thesurfacearea, a froth overflow eaten ing along the length of the chamber, alongitudinal launder adjacent to the chamber, means for moving thecolumn of mineral-laden gas bubbles immediately upon formation in asubstantially lateral direction towards the launder to subject thecolumn of gas bubbles .to a selective cleaning action by passagelaterally over the remaining'longitudinal surface of the ore pulpthereby permitting certain portionsv of the ore to return to thelongitudinally flowing ore pulp and to be carried further along into thechamber "for retreatlnent, said chamher having: outwardly inclined sidewalls to facilitate the return of said certain portions of the to thelongitudinally flowing ore in testimony whereof I allix my signatnre.

EDWIN B. MALMROS.

